DE 10 2005 040 952 A1 (corresponds to U.S. Pat. No. 7,232,323) describes such an electrical zero force plug connector. This plug connector includes a plug sleeve housing (or socket housing) and an assembly connector. The socket housing has two housing parts including a protective housing part and a locking housing part. The housing parts can be inserted into one another in two latching positions. The clamping sleeves of the sleeve contacts are connected to the protective housing part. When the housing parts are in a first latching position, the clamping sleeves are held open so that connector pins of the assembly connector (i.e., the mating connector) can be connected almost force-free to the sleeve contacts. Insertion of the assembly connector releases the lock of the latching connection between the housing parts. This brings the housing parts together into a second latching position with respect to one another. When the housing parts are in the second latching position, contact blades of the sleeve contacts are compressed against the connector pins of the assembly connector.
The latching mechanism between the housing parts enables the connector pins of the assembly connector to be inserted almost force-free into the sleeve contacts. A contact force between the contact blades of the sleeve contacts and the connector pins is produced only in the final phase of inserting the connector pins into the sleeve contacts. In order that mechanical effects on the protective housing part or the assembly connector are not transmitted to the electrical contact elements connected with one another, which can cause the contact elements to become disconnected, an elastic snap-fit rocker is formed on an external wall of the protective housing part. While attaching to the assembly connector, a spring arm of the snap-fit rocker latches with a detent on the assembly connector and thereby connects both plug connector components to one another in a form-fitting manner. Opening this latching connection as needed to separate the two plug connector components can be achieved by exerting pressure on the free spring arm of the snap-fit rocker.
In this zero force plug connector, displacement of the clamping sleeves and latching of the snap-fit rocker of the protective housing part onto the detent of the assembly connector can be achieved mechanically independently of one another. There is thus no danger that when the clamping sleeves slide the latching connection between the protective housing part and the assembly connector breaks. This is because for the mutually latched protective housing part and assembly connector the clamping sleeves also slide until they reach their end position.